Flare Nut 　 Part No. Ref. No. Description 441-04 04 1/4" O.D. Tube 441-06 06 3/8" O.D. Tube 441-08 08 1/2" O.D. Tube 441-10 10 5/8" O.D. Tube 441-12 12 3/4" O.D. Tube